Crystal structure, lattice vibrational characteristics, and dielectric properties of Ba(Mg1/2Mo1/2)O3 ceramics sintered at different temperatures

Double perovskite structured Ba(Mg 1/2 Mo 1/2 )O 3 (BMM) ceramics were prepared by traditional solid sintering methods at different sintering temperatures (T s =1250–1325 °C). X-ray diffraction (XRD) data proved a 1:1 ordered face-centered cubic lattice (Fm-3 m), and the ceramic sintered at 1300 °C obtained maximum relative density. The lattice vibration characteristics were identified by Raman spectroscopy and far-infrared reflection spectroscopy. Based on the far-infrared data, a four-parameter semi-quantum model (FPSQ) was applied to calculate the intrinsic properties of BMM ceramics, and the obtained results approximated the measured values. The Raman shift of the BMM F 2g (B) mode (attributed to the centrosymmetric vibration of Ba atom) was shown to be negatively correlated with the corrected permittivity and Ba-O bond length. With increasing sintering temperature (T s ), the relative density is positively correlated with the quality factor ( Q   ×   f) , and the change of Ba-O bond length leads to distortion of the oxygen octahedron, which is positively correlated with the dielectric constant. The sintered BMM ceramics obtained their best dielectric properties at 1300 °C ( ε r = 4.987, Q   ×   f   =  23,069 GHz, f  = 11.16 GHz).